China has the largest number of the user of web 2.0 such as messengers and blogs, as of 2008 year. Chinese Internet digital market will grow from $85 billion in 2007 to $264 billion in 2015. The importance of Chinese Internet business is increasing, because of its size and growth potential. This research is focused on following two questions. First, what are the major characteristics of social networking services in China? In order to find out the answer about this question, the case study on Tencent QQ and Sina Poco, the most representative social networking services company in China, was done. And the reason of the use of social networking services, their contents, and the attitude toward the paid service were identified. Second, what are the major factors influencing the use of social networking services in China. User participation, network effect, usefulness, and system quality were inferred as the factors influencing the use. These factors were based on motivation theory, technology acceptance model, and the related research papers. This research model was proved by data analysis using Partial Least Square. As results, the use of social networking services was influenced by usefulness, network effect, user participation, and system quality. But social influence was not significant of the use of social networking services.